In the mid-1880s both Daimler and Benz began to build the first automobiles for mass production. Shortly thereafter Henry Ford began producing the Model T in the United States. Since that time, the automobile and its various components have been constantly re-engineered and improved upon, the goal being to balance factors such as cost, quality, comfort, performance and efficiency.
One essential component to the automobile is the container, i.e. the fuel tank, which holds the source of power, i.e. fuel. Although it may seem like the job of the fuel tank is a simple one, to hold the fuel, the demands of other external factors have influenced various transformations and versions of fuel tanks as the automobile has developed over the last century.
Engineers, when designing fuel tanks, attempt to maximize capacity and efficiency in retrieving the fuel from the tank while minimizing the complexity and associated manufacturing and repair costs. This factors must be balanced while still maintaining a standard of quality and reliability.
A major hurdle to overcome is often a lack of space in the automobile for a large, rectangular shaped fuel tank. As a result, fuel tanks have ended up being odd shaped containers, reaching into various apertures and gaps to take full advantage of all available space to store a maximum amount of fuel. This is typically done because the larger the fuel tank, the greater the range of the vehicle, and the fewer times the owner has to stop to refuel.
If space was not an issue, then the fuel tank would be designed to have a funnel-shaped base with a fuel pump inlet or pickup being located at the base of the funnel, such that all of the fuel in the fuel tank would be readily retrieved. However, because of the lack of space, fuel tanks often have a flat, or a substantially flat base. This creates a fundamental problem in retrieving the fuel, especially the last few gallons. When there is a small amount of fuel left in the fuel tank, various effects resulting from common driving procedures, like stopping, starting, turning, etc., cause the fuel to be forced away from the fuel pump inlet or pickup and collect along a side(s) and/or in a corner(s) of the fuel tank. When this occurs, the flow of fuel to the engine is interrupted, a drawback that engineers try to avoid.
If the design of the fuel tank does not take into consideration these aforementioned effects, the fuel system is not able to retrieve and pump the entire contents of the fuel tank and a portion of the fuel carried in the fuel tank becomes essentially useless, e.g. an 11 gallon fuel tank may only have 9.5 gallons of usable fuel. Engineers have studied this problem and proposed various methods to retrieve substantially all of the fuel from the fuel tank.
Some previous designs have included the concept of a fuel delivery module or reservoir within the fuel tank. This basic design involves a support extending from the top of the tank towards a bottom. A pump/reservoir component is slidably connected to the support such that the pump/reservoir component may move vertically. The pump/reservoir component rests on a bottom inside surface of the gasoline tank, and is typically supported by a hanger or a suspension system from above, which allows it to descend into the tank, along the support structure, as the fuel is consumed. The pump (typically within the reservoir) supplies fuel from the main fuel tank and delivers it directly to the engine as well as continuously supplying a small reservoir tank. The excess fuel from the reservoir tank overflows a top of the reservoir into the main tank.
At such time when the pump cannot supply any fuel from the main tank, because the main tank is empty, or the remaining fuel in the main tank is being forced away from the pump due to operation of the vehicle, the pump will draw fuel from the reservoir tank. The reservoir is designed to ensure that there is always fuel located adjacent the fuel pump inlet for all driving conditions (starts, stops, turns, etc.).
The systems that have been developed thus far to carry out these functions are complex and expensive. As stated previously, they have components such as support structures, hangers, and pumps that are enclosed in the tank. They are generally complex and expensive to manufacture, install and/or repair. If the system malfunctions, or a pump fails, it is a complicated process to repair the system; and if the pump needs to be replaced, other expensive components must also be replaced because they are interconnected with the pump. In the competitive world of automobile manufacturing, companies constantly strive to make vehicles that are of high quality, but cost the least amount of money to assemble, and the least amount of money to maintain. Until now, typical fuel tank pump repairs have included a lot of extra as well as superfluous costs.